A 0.040 kg ball tied to a string moves in a circle that has a radius of 0.700 m. The period is 1.5 s. What is the tangential velocity of the ball?

The reflection of the candle in the concave mirror formed an upside-down virtual image that is smaller than the candle.in other words. the answer is the third option, c

Idon't know it i just need my points lol

Answer(a)   the matererials that are in contact, the two materials and the nature of their surfaces/// (b)/// the force pushing the two surfaces together, pushing the surfaces together causes the more of the asperities to come together and increases the surface area in contact with each other